casualty

A casualty is a person who is injured, killed, missing, or otherwise affected by an accident, disaster, or armed conflict. The term is broader than fatality, which typically denotes death; casualties can include injuries as well as deaths and other losses. Casualties are counted in contexts such as wars, terrorist acts, traffic crashes, natural disasters, and disease outbreaks, reflecting the full range of harm experienced by individuals and communities.

In medical settings, the word casualty has specialized usage. In some varieties of English, a casualty refers to a person arriving at a hospital for treatment after an injury or sudden illness. The term “casualty department” or “casualty ward” has historically been used in British hospitals to describe what is now commonly called the emergency department in many countries.

In military contexts, casualties include those killed, wounded, missing, or captured. In humanitarian and international-law discussions, civilian casualties are of particular concern, highlighting harm to non-combatants during hostilities and the protections afforded to civilians under law.

Etymology traces casualty to Middle French casualité, from Latin casus meaning a chance or accident. The word has carried the sense of mischance or harm arising from unforeseen events across centuries, and today it remains a standard term in public health, emergency response, and conflict reporting.